In many countries, the first step is to obtain a restraining order from a civil court as part of your divorce or custody proceedings or as a stand-alone measure.
In some countries, the police applies to the court for an emergency protection order on your behalf. The difference between a protection order and a restraining order is that the former is obtained following an incident of domestic violence involving injury or damage to property, it is available immediately, granted at the police's request, and issued even outside court hours.
Many restraining orders are granted ex parte, without the knowledge or presence of your abusive partner, based solely on a signed and sworn affidavit submitted by you. A typical emergency restraining order forbids the offender from visiting certain locations such as the children's schools, your workplace, or your home. It is later reviewed. At the review you should produce evidence of the abuse and witnesses. If the emergency or temporary order upheld it is fixed for a period of time at the judge's discretion.
Always carry the restraining order with you and leave copies at your place of employment and at your children's day-care and schools. You will have to show it to the police if you want to get your abuser arrested when he violates its terms. Breach of the restraining order is a criminal offence.
(From the book "Malignant Self-love: Narcissism Revisited" by Sam Vaknin - Click on this link to purchase: http://www.narcissistic-abuse.com/thebook.html)